The present invention relates to methods and apparatus for forming and inspecting package seals. Existing methods used to verify the quality of package seals include: individual manual and visual inspection, destructive testing, and testing in vacuum chambers. Other methods of verification generally include statistical sampling techniques characterized by the frequency with which a product is inspected for desired seal quality.
Some techniques of verification include the utilization of machine vision with the purpose of identifying leaks in the seal areas of packaged products. For example, an infra red thermal sensing camera can be used to detect residual heat on the seal of a package subsequent to a packaging procedure. Such techniques generally require a relatively high level of package consistency and precise timing when moving or manipulating the sealed package from sealing to verification.
Other techniques of verification include electromechanical methods where physical pressure is applied to a packaged product, such as a bag. For example, precision feedback devices can be utilized to test characteristics of the packaged product at more than one stage of the manufacturing process. Testing the product at various stages can indicate whether a differential exists between stages. For example, in the food industry, bags are generally inflated and sealed to help protect brittle products. Feedback devices can be implemented to test the pressure of the sealed bag at different stages of manufacturing to determine the presence of leaks.
Various other techniques are utilized to determine the seal quality of packaged products.